Re: [PERFORM] BETWEEN optimizer problems with single-value range - Mailing list pgsql-hackers

From Merlin Moncure
Subject Re: [PERFORM] BETWEEN optimizer problems with single-value range
Date
Msg-id [email protected]
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In response to BETWEEN optimizer problems with single-value range  ("Kevin Grittner" <[email protected]>)
List pgsql-hackers
On 3/15/06, Andreas Kretschmer <[email protected]> wrote:
> Merlin Moncure <[email protected]> schrieb:
>
> > On 3/15/06, Kevin Grittner <[email protected]> wrote:
> > > Attached is a simplified example of a performance problem we have seen,
> > > with a workaround and a suggestion for enhancement (hence both the
> > > performance and hackers lists).
> >
> >
> > Hi Kevin.  In postgres 8.2 you will be able to use the row-wise
>
> 8.2? AFAIK, Feature freeze in juni/juli this year...
> Release august/september.

yes, but I was addressing kevin's point about enhancing the server...

> > comparison for your query which  should guarantee good worst case
> > performance without having to maintain two separate query forms.  it
>
> Perhaps, a bitmap index scan (since 8.1) are useful for such querys.
> Thats why i asked which version.

I think you will find that reading a range of records from a table
ordered by an index utilizing the 8.2 comparison feature is much
faster than a bitmap index scan.

Merlin

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